diff --git a/src/java.base/share/classes/java/util/regex/CharPredicates.java b/src/java.base/share/classes/java/util/regex/CharPredicates.java
index f33d2784124..c168a1443c0 100644
--- a/src/java.base/share/classes/java/util/regex/CharPredicates.java
+++ b/src/java.base/share/classes/java/util/regex/CharPredicates.java
@@ -169,11 +169,15 @@ static final CharPredicate WORD() {
 
     /////////////////////////////////////////////////////////////////////////////
 
-    private static CharPredicate getPosixPredicate(String name) {
+    private static CharPredicate getPosixPredicate(String name, boolean caseIns) {
         switch (name) {
             case "ALPHA": return ALPHABETIC();
-            case "LOWER": return LOWERCASE();
-            case "UPPER": return UPPERCASE();
+            case "LOWER": return caseIns
+                              ? LOWERCASE().union(UPPERCASE(), TITLECASE())
+                              : LOWERCASE();
+            case "UPPER": return caseIns
+                              ? UPPERCASE().union(LOWERCASE(), TITLECASE())
+                              : UPPERCASE();
             case "SPACE": return WHITE_SPACE();
             case "PUNCT": return PUNCTUATION();
             case "XDIGIT": return HEX_DIGIT();
@@ -187,7 +191,7 @@ private static CharPredicate getPosixPredicate(String name) {
         }
     }
 
-    private static CharPredicate getUnicodePredicate(String name) {
+    private static CharPredicate getUnicodePredicate(String name, boolean caseIns) {
         switch (name) {
             case "ALPHABETIC": return ALPHABETIC();
             case "ASSIGNED": return ASSIGNED();
@@ -196,11 +200,17 @@ private static CharPredicate getUnicodePredicate(String name) {
             case "IDEOGRAPHIC": return IDEOGRAPHIC();
             case "JOINCONTROL": return JOIN_CONTROL();
             case "LETTER": return LETTER();
-            case "LOWERCASE": return LOWERCASE();
+            case "LOWERCASE": return caseIns
+                                  ? LOWERCASE().union(UPPERCASE(), TITLECASE())
+                                  : LOWERCASE();
             case "NONCHARACTERCODEPOINT": return NONCHARACTER_CODE_POINT();
-            case "TITLECASE": return TITLECASE();
+            case "TITLECASE": return caseIns
+                                  ? TITLECASE().union(LOWERCASE(), UPPERCASE())
+                                  : TITLECASE();
             case "PUNCTUATION": return PUNCTUATION();
-            case "UPPERCASE": return UPPERCASE();
+            case "UPPERCASE": return caseIns
+                                  ? UPPERCASE().union(LOWERCASE(), TITLECASE())
+                                  : UPPERCASE();
             case "WHITESPACE": return WHITE_SPACE();
             case "WORD": return WORD();
             case "WHITE_SPACE": return WHITE_SPACE();
@@ -211,16 +221,16 @@ private static CharPredicate getUnicodePredicate(String name) {
         }
     }
 
-    public static CharPredicate forUnicodeProperty(String propName) {
+    public static CharPredicate forUnicodeProperty(String propName, boolean caseIns) {
         propName = propName.toUpperCase(Locale.ROOT);
-        CharPredicate p = getUnicodePredicate(propName);
+        CharPredicate p = getUnicodePredicate(propName, caseIns);
         if (p != null)
             return p;
-        return getPosixPredicate(propName);
+        return getPosixPredicate(propName, caseIns);
     }
 
-    public static CharPredicate forPOSIXName(String propName) {
-        return getPosixPredicate(propName.toUpperCase(Locale.ENGLISH));
+    public static CharPredicate forPOSIXName(String propName, boolean caseIns) {
+        return getPosixPredicate(propName.toUpperCase(Locale.ENGLISH), caseIns);
     }
 
     /////////////////////////////////////////////////////////////////////////////
@@ -254,14 +264,23 @@ static CharPredicate forUnicodeBlock(String name) {
 
     // unicode categories, aliases, properties, java methods ...
 
-    static CharPredicate forProperty(String name) {
+    static CharPredicate forProperty(String name, boolean caseIns) {
         // Unicode character property aliases, defined in
         // http://www.unicode.org/Public/UNIDATA/PropertyValueAliases.txt
         switch (name) {
             case "Cn": return category(1<<Character.UNASSIGNED);
-            case "Lu": return category(1<<Character.UPPERCASE_LETTER);
-            case "Ll": return category(1<<Character.LOWERCASE_LETTER);
-            case "Lt": return category(1<<Character.TITLECASE_LETTER);
+            case "Lu": return category(caseIns ? (1 << Character.LOWERCASE_LETTER) |
+                                                 (1 << Character.UPPERCASE_LETTER) |
+                                                 (1 << Character.TITLECASE_LETTER)
+                                               : (1 << Character.UPPERCASE_LETTER));
+            case "Ll": return category(caseIns ? (1 << Character.LOWERCASE_LETTER) |
+                                                 (1 << Character.UPPERCASE_LETTER) |
+                                                 (1 << Character.TITLECASE_LETTER)
+                                               : (1 << Character.LOWERCASE_LETTER));
+            case "Lt": return category(caseIns ? (1 << Character.LOWERCASE_LETTER) |
+                                                 (1 << Character.UPPERCASE_LETTER) |
+                                                 (1 << Character.TITLECASE_LETTER)
+                                               : (1 << Character.TITLECASE_LETTER));
             case "Lm": return category(1<<Character.MODIFIER_LETTER);
             case "Lo": return category(1<<Character.OTHER_LETTER);
             case "Mn": return category(1<<Character.NON_SPACING_MARK);
@@ -338,32 +357,43 @@ static CharPredicate forProperty(String name) {
             case "Cntrl": return ctype(ASCII.CNTRL);  // Control characters
             case "Digit": return range('0', '9');     // Numeric characters
             case "Graph": return ctype(ASCII.GRAPH);  // printable and visible
-            case "Lower": return range('a', 'z');     // Lower-case alphabetic
+            case "Lower": return caseIns ? ctype(ASCII.ALPHA)
+                                         : range('a', 'z');     // Lower-case alphabetic
             case "Print": return range(0x20, 0x7E);   // Printable characters
             case "Punct": return ctype(ASCII.PUNCT);  // Punctuation characters
             case "Space": return ctype(ASCII.SPACE);  // Space characters
-            case "Upper": return range('A', 'Z');     // Upper-case alphabetic
+            case "Upper": return caseIns ? ctype(ASCII.ALPHA)
+                                         : range('A', 'Z');     // Upper-case alphabetic
             case "XDigit": return ctype(ASCII.XDIGIT); // hexadecimal digits
 
             // Java character properties, defined by methods in Character.java
-            case "javaLowerCase": return java.lang.Character::isLowerCase;
-            case "javaUpperCase": return  Character::isUpperCase;
-            case "javaAlphabetic": return java.lang.Character::isAlphabetic;
-            case "javaIdeographic": return java.lang.Character::isIdeographic;
-            case "javaTitleCase": return java.lang.Character::isTitleCase;
-            case "javaDigit": return java.lang.Character::isDigit;
-            case "javaDefined": return java.lang.Character::isDefined;
-            case "javaLetter": return java.lang.Character::isLetter;
-            case "javaLetterOrDigit": return java.lang.Character::isLetterOrDigit;
-            case "javaJavaIdentifierStart": return java.lang.Character::isJavaIdentifierStart;
-            case "javaJavaIdentifierPart": return java.lang.Character::isJavaIdentifierPart;
-            case "javaUnicodeIdentifierStart": return java.lang.Character::isUnicodeIdentifierStart;
-            case "javaUnicodeIdentifierPart": return java.lang.Character::isUnicodeIdentifierPart;
-            case "javaIdentifierIgnorable": return java.lang.Character::isIdentifierIgnorable;
-            case "javaSpaceChar": return java.lang.Character::isSpaceChar;
-            case "javaWhitespace": return java.lang.Character::isWhitespace;
-            case "javaISOControl": return java.lang.Character::isISOControl;
-            case "javaMirrored": return java.lang.Character::isMirrored;
+            case "javaLowerCase": return caseIns ? c -> Character.isLowerCase(c) ||
+                                                        Character.isUpperCase(c) ||
+                                                        Character.isTitleCase(c)
+                                                 : Character::isLowerCase;
+            case "javaUpperCase": return caseIns ? c -> Character.isUpperCase(c) ||
+                                                        Character.isLowerCase(c) ||
+                                                        Character.isTitleCase(c)
+                                                 : Character::isUpperCase;
+            case "javaAlphabetic": return Character::isAlphabetic;
+            case "javaIdeographic": return Character::isIdeographic;
+            case "javaTitleCase": return caseIns ? c -> Character.isTitleCase(c) ||
+                                                   Character.isLowerCase(c) ||
+                                                   Character.isUpperCase(c)
+                                            : Character::isTitleCase;
+            case "javaDigit": return Character::isDigit;
+            case "javaDefined": return Character::isDefined;
+            case "javaLetter": return Character::isLetter;
+            case "javaLetterOrDigit": return Character::isLetterOrDigit;
+            case "javaJavaIdentifierStart": return Character::isJavaIdentifierStart;
+            case "javaJavaIdentifierPart": return Character::isJavaIdentifierPart;
+            case "javaUnicodeIdentifierStart": return Character::isUnicodeIdentifierStart;
+            case "javaUnicodeIdentifierPart": return Character::isUnicodeIdentifierPart;
+            case "javaIdentifierIgnorable": return Character::isIdentifierIgnorable;
+            case "javaSpaceChar": return Character::isSpaceChar;
+            case "javaWhitespace": return Character::isWhitespace;
+            case "javaISOControl": return Character::isISOControl;
+            case "javaMirrored": return Character::isMirrored;
             default: return null;
         }
     }
diff --git a/src/java.base/share/classes/java/util/regex/Pattern.java b/src/java.base/share/classes/java/util/regex/Pattern.java
index 850c52871df..e3e8fec3205 100644
--- a/src/java.base/share/classes/java/util/regex/Pattern.java
+++ b/src/java.base/share/classes/java/util/regex/Pattern.java
@@ -2885,7 +2885,7 @@ private CharPredicate family(boolean singleLetter, boolean isComplement) {
                     break;
                 case "gc":
                 case "general_category":
-                    p = CharPredicates.forProperty(value);
+                    p = CharPredicates.forProperty(value, has(CASE_INSENSITIVE));
                     break;
                 default:
                     break;
@@ -2901,17 +2901,17 @@ private CharPredicate family(boolean singleLetter, boolean isComplement) {
             } else if (name.startsWith("Is")) {
                 // \p{IsGeneralCategory} and \p{IsScriptName}
                 name = name.substring(2);
-                p = CharPredicates.forUnicodeProperty(name);
+                p = CharPredicates.forUnicodeProperty(name, has(CASE_INSENSITIVE));
                 if (p == null)
-                    p = CharPredicates.forProperty(name);
+                    p = CharPredicates.forProperty(name, has(CASE_INSENSITIVE));
                 if (p == null)
                     p = CharPredicates.forUnicodeScript(name);
             } else {
                 if (has(UNICODE_CHARACTER_CLASS)) {
-                    p = CharPredicates.forPOSIXName(name);
+                    p = CharPredicates.forPOSIXName(name, has(CASE_INSENSITIVE));
                 }
                 if (p == null)
-                    p = CharPredicates.forProperty(name);
+                    p = CharPredicates.forProperty(name, has(CASE_INSENSITIVE));
             }
             if (p == null)
                 throw error("Unknown character property name {In/Is" + name + "}");
diff --git a/test/jdk/java/util/regex/RegExTest.java b/test/jdk/java/util/regex/RegExTest.java
index cb7e56f4195..bd722815a0c 100644
--- a/test/jdk/java/util/regex/RegExTest.java
+++ b/test/jdk/java/util/regex/RegExTest.java
@@ -35,7 +35,7 @@
  * 8027645 8035076 8039124 8035975 8074678 6854417 8143854 8147531 7071819
  * 8151481 4867170 7080302 6728861 6995635 6736245 4916384 6328855 6192895
  * 6345469 6988218 6693451 7006761 8140212 8143282 8158482 8176029 8184706
- * 8194667 8197462 8184692 8247546
+ * 8194667 8197462 8184692 8247546 8305733
  *
  * @library /test/lib
  * @build jdk.test.lib.RandomFactory
@@ -170,6 +170,7 @@ public static void main(String[] args) throws Exception {
         grapheme();
         expoBacktracking();
         invalidGroupName();
+        caseInsensitivePMatch();
 
         if (failure) {
             throw new
@@ -4932,4 +4933,63 @@ private static void invalidGroupName() {
         }
         report("Invalid capturing group names");
     }
+
+    // This test is for 8305733
+    private static void caseInsensitivePMatch() {
+        for (String input : List.of("abcd", "AbCd", "ABCD")) {
+            for (String pattern : List.of("abcd", "aBcD", "[a-d]{4}",
+                    "(?:a|b|c|d){4}", "\\p{Lower}{4}", "\\p{Ll}{4}",
+                    "\\p{IsLl}{4}", "\\p{gc=Ll}{4}",
+                    "\\p{general_category=Ll}{4}", "\\p{IsLowercase}{4}",
+                    "\\p{javaLowerCase}{4}", "\\p{Upper}{4}", "\\p{Lu}{4}",
+                    "\\p{IsLu}{4}", "\\p{gc=Lu}{4}", "\\p{general_category=Lu}{4}",
+                    "\\p{IsUppercase}{4}", "\\p{javaUpperCase}{4}",
+                    "\\p{Lt}{4}", "\\p{IsLt}{4}", "\\p{gc=Lt}{4}",
+                    "\\p{general_category=Lt}{4}", "\\p{IsTitlecase}{4}",
+                    "\\p{javaTitleCase}{4}", "[\\p{Lower}]{4}", "[\\p{Ll}]{4}",
+                    "[\\p{IsLl}]{4}", "[\\p{gc=Ll}]{4}",
+                    "[\\p{general_category=Ll}]{4}", "[\\p{IsLowercase}]{4}",
+                    "[\\p{javaLowerCase}]{4}", "[\\p{Upper}]{4}", "[\\p{Lu}]{4}",
+                    "[\\p{IsLu}]{4}", "[\\p{gc=Lu}]{4}",
+                    "[\\p{general_category=Lu}]{4}", "[\\p{IsUppercase}]{4}",
+                    "[\\p{javaUpperCase}]{4}", "[\\p{Lt}]{4}", "[\\p{IsLt}]{4}",
+                    "[\\p{gc=Lt}]{4}", "[\\p{general_category=Lt}]{4}",
+                    "[\\p{IsTitlecase}]{4}", "[\\p{javaTitleCase}]{4}"))
+            {
+                Predicate<String> p = Pattern.compile(pattern, Pattern.CASE_INSENSITIVE).asPredicate();
+                if (!p.test(input)) {
+                    failCount++;
+                }
+            }
+        }
+
+        for (String input : List.of("\u01c7", "\u01c8", "\u01c9")) {
+            for (String pattern : List.of("\u01c7", "\u01c8", "\u01c9",
+                    "[\u01c7\u01c8]", "[\u01c7\u01c9]", "[\u01c8\u01c9]",
+                    "[\u01c7-\u01c8]", "[\u01c8-\u01c9]", "[\u01c7-\u01c9]",
+                    "\\p{Lower}", "\\p{Ll}", "\\p{IsLl}", "\\p{gc=Ll}",
+                    "\\p{general_category=Ll}", "\\p{IsLowercase}",
+                    "\\p{javaLowerCase}", "\\p{Upper}", "\\p{Lu}",
+                    "\\p{IsLu}", "\\p{gc=Lu}", "\\p{general_category=Lu}",
+                    "\\p{IsUppercase}", "\\p{javaUpperCase}",
+                    "\\p{Lt}", "\\p{IsLt}", "\\p{gc=Lt}",
+                    "\\p{general_category=Lt}", "\\p{IsTitlecase}",
+                    "\\p{javaTitleCase}", "[\\p{Lower}]", "[\\p{Ll}]",
+                    "[\\p{IsLl}]", "[\\p{gc=Ll}]",
+                    "[\\p{general_category=Ll}]", "[\\p{IsLowercase}]",
+                    "[\\p{javaLowerCase}]", "[\\p{Upper}]", "[\\p{Lu}]",
+                    "[\\p{IsLu}]", "[\\p{gc=Lu}]",
+                    "[\\p{general_category=Lu}]", "[\\p{IsUppercase}]",
+                    "[\\p{javaUpperCase}]", "[\\p{Lt}]", "[\\p{IsLt}]",
+                    "[\\p{gc=Lt}]", "[\\p{general_category=Lt}]",
+                    "[\\p{IsTitlecase}]", "[\\p{javaTitleCase}]"))
+            {
+                Predicate<String> p = Pattern.compile(pattern, Pattern.CASE_INSENSITIVE
+                                                       | Pattern.UNICODE_CHARACTER_CLASS).asPredicate();
+                if (!p.test(input)) {
+                    failCount++;
+                }
+            }
+        }
+    }
 }